1. Field of the Invention
This invention relates to a method of beneficiating fine particulate coal and more particularly to a method of beneficiating coal through an aqueous slurry technique with subsequent water removal.
2. Description of the Prior Art
The burning of fine particulate coal by atomization has found acceptance as a method of more fully utilizing coal resources. Because coal having a particle size of 200 microns or less is finely divided, it has a large surface area which aids in its complete combustion. Further, finely divided coal has a high degree of porosity, and when the pores are impregnated with water and the coal is subsequently burned, the water superheats and explodes the coal particle thus providing more surface area for efficient burning. The impregnation of the coal with water has presented problems in that large amounts of water, i.e., about 80 percent, have been used to slurry and impregnate the coal. The separation of the water to obtain a high coal product has been accomplished by pumping the coal into settling ponds, allowing the coal to flocculate, and pumping off the excess water. Obviously this process involves time and space and has many undesirable characteristics.
In a similar process exemplified by U.S. Pat. No. 3,941,552, a process for forming an emulsion of water, oil and coal is provided which includes treating a slurry of the three constituents in an ultrasonic reactor to form a stable emulsion. This emulsion is subsequently burned in an oil type burner.
In accordance with the present invention, a process for the beneficiation of coal is provided which washes the coal during slurrying, impregnates the coal and concentrates the slurry to a high coal content.